Amber



March 3,

Filed Sept.

FIG. IA.

1964 s. M. PHELPS ETAL ALT. TRANs- ALT. SEL. FER REs,

FLIGHT DATA DISPLAY 4 Sheets-Sheet l @HDC] [COJ,@.

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we a a C] a m m n [3 [3 a a C] [:1 8 @1 m 22 24 coNTR 9 PAN CANCEL RESET Cg CTloN O O BUTTONS FLlGHT DATA /CP KEYBOARD REsERvA N }BUTTO 9 9 g g INVENTO S.M. PH s COLOR SYMBOL REsERvATIoN INDIcATIoN FADA AMBER ALTITUDE RESERVATION BY GREEN LOCAL OCCUPANCY RED ([11) DISTANT OCCUPANCY THEIR ATTORNEY March 3, 1964 s. M. PHELPS ETAL 3,123,300

AIR TRAFFIC CONTROL MACHINE Filed Sept. 15, 1960 4 Sheets-Sheet 2 INVENTORS. S.M. PHELPS AND F. A. DALY jww THEIR ATTORNEY FIG. 2.

March 3, 1964 s. M. PHELPS ETAL 3,123,800

AIR TRAFFIC CONTROL MACHINE Filed Sept. 15, 1960 4 Sheets-Sheet 3' FIG. 5. FIG. 4. 7 FIG. 6.

TO CONTROL ENERGY INVENTORS. S.M. PHELPS AND F. A. DALY EMMJ THEIR ATTORNEY March 3, 1964 Filed Sept. 15, 19601 FIG. 8.

S. M. PHELPS ETAL AIR TRAFFIC CONTROL MACHINE 4 Sheets-Sheet 4 THEIR ATTORNEY United States Patent 0 3,123,800 Alli TRAFFEQ QGNTROL MACHINE Stuart M. Phelps and Frank A. Daily, Rochester, N.Y., assiguors to General digital fiorporation Filed Sept. i5, 196%, Ser. No. 56,231 6 Claims. Cl. 340-43} This invention relates to an air trafiic control machine, and more particularly pertains to means for facili tating the assemblage and maintenance of such machine.

The inception of airplane flight scheduling between designated locations has required that some means be provided for governing the flights between such locations. In this respect, the hazards encountered by a plurality of planes flying in a restricted area wherein the weather conditions do not permit visual contact of one airplane with another airplane has necessitated governing from the ground locations. The control from ground locations has been, and is, accomplished by the provision of a system for delineating the respective routes of airplanes in flight. From the early days of air traflic iiferent systems have been employed according to the amount of air tratflc.

The first route delineation system which was employed was merely a blackboard arrangement wherein the controllers wrote the flight data for different airplane flights in particular blocks and corrected such flight data according to the location of respective airplanes in flight. A later system employed flight progress boards each of which was assigned a particular fix within a route between two locations with flight progress strips having flight data written thereon being moved from flight progress board to flight progress board according to the progress of an airplane within a route, thereby providing a visual indication of the general progress of an airplane in flight Within a particular route. As air traffic continued to increase, it was found that this method of route delineation entailed undue manual effort and consumed too much of the working time of controllers. In order to overcome this, changeable display indicators were devised and employed to reduce the manual operations required but to still provide the necessary flight data in rder to allow the controller to properly govern airplane flights within a designated route.

The types of changeable display indicators devised for displtying flight data may be generally categorized as noncoded and coded types of indicators. The noncoded type of indicator is distinctive in that control energy is supplied over only one or all but one of a plurality of control buses for operating a selected indicator, whereas the control buses for a coded type of indicator are energized in different binary code combinations for operating a selected indicator. Irrespective of the type of changeable display indicator that has been employed in air traflic control systems as well as other display systems, however, it has been the practice to employ wires for the control buses over which control energy is supplied in either a noncoded or coded manner. Moreover, the use of a plurality of control buses with a num ber of changeable display indicators has required that wirin connections be made between the plurality of control buses and respective indicators. Also, the use of the coded type of indicator wherein at least two changeable contacts are normally closed in each display position has required some form of isolation between the respective indicators and the common control buses. This isolation has taken, for example, the forms of relay contacts and diodes.

The continuously increasing amount of air traffic in recent years has required that a route delineation system be devised which is flexible in accordance with the re quirements of such increased air traffic. That is, when 3,l23,8 Patented Mar. 3, 1964 a system is once installed at a particular airport location, it should be readily adaptable thereat according to the demands of air trafiic as governed by that location for an indefinite period. Thus, the route delineation system should be initially constructed in such a manner so that it can be readily modified to handle the increased air traffic.

According to the present invention an air traffic control machine is provided wherein several laterally disposed posting indicators are arranged in rows and colums for posting flight information, one row of indicators being provided for each of several flight altitudes. A printed circuit board is provided for the control of each indicator, and it is disposed elevationally adjoining one end of its associated indicator, to which it is coupled.

The adjoining longitudinal edges of each of the circuit boards in each column of boards are supported and con nected together electrically by a longitudinal connector which has oppositely disposed longitudinal slots for receiving edges of the circuit boards with which the connector is associated. The connector has a plurality of conductors extending between the oppositely disposed slots for connecting circuits from the board for one flight elevation to the board for the next flight elevation in the same column.

In the present invention, it is noted that several advantages are attained which have been heretofore unattainable in the prior art. That is, a plurality of changeable display indictors in the form of a module may be readily connected to an already established system by employing the combination of elements in this invention. The overall system is thus made flexible in that the changeable display indicators may be added by modules in accordance with increased air trafflc. Moreover, the combination of elements of this invention simplifies the maintenance of individual control circuits for the changeable display indicators in that a control circuit for a particular indicator may readily be removed and replaced by another control circuit without requiring sol dering, thus tending to maintain the overall system in operation substantially at all times.

An object of the present invention is to provide an air traflic control machine wherein several posting indicators are disposed laterally in rows and columns, each indicator having an elevationally disposed control circuit board detachably secured to one end thereof.

Another object of the present invention is to dispose a quickly detachable connector between the edges of the boards in each column of boards for the purpose of completing electrical connections between boards and for the purpose of spacing and supporting the circuit boards in the control machine.

Another object of the present invention is to provide a yoke for securing each row of connectors in position in the control machine, the yoke having a quickly detachable connection with each of the connectors to facilitate removal for maintenance purposes.

Other objects, purposes and characteristic features of this invention will be in part obvious from the accompanying drawings, and in part pointed out as the description of the invention progresses.

in describing the invention in detail, reference will be made to the accompanying drawings, in which like reierence characters designate corresponding parts throughout the several views, and in which:

FIG. 1A is a front elevational view of an air traffic control machine showing the control panel and arrangement of changeable display indicators in modular form;

FIG. 1B is a chart showing reservation indications and symbols and colors employed to denote such reservation indications as displayable by the changeable display indicators;

FIG. 2 is an isometric view of an air traffic control machine showing the combination of elements of this invention as employed when assembling the modules of changeable display indicator in modular form;

FIG. 3 is a detailed view illustrating the manner in which the combination of elements of this invention are employed to mechanically and electrically connect two changeable display indicators;

FIG. 4 is a side View of the connector included in FIG. 3 showing the arrangement of the plurality of spring biased members included therewith;

PEG. 5 is a sectional view of the connector talren on line 5-5 in H6. 4 for showing the manner in which a spring biased member and the insulating member would appear in assembled form;

FIG. 6 is a top View of the connector included in FIG. 3 showing the arrangement of the plurality of spring biased members included therewith;

FIG. 7 is a detailed view of the reverse side of one printed circuit board shown in FIG. 3 with several representative elements included of the control circuit for a changeable display indicator being connected thereto; and

FIG. 8 is a rear view of the air trafiic control machine shown in FIG. 2 illustrating the wire connections through individual connectors to printed circuit boards employed with the changeable display indicators arranged in modules.

Inasmuch as the present invention is applicable to an air trafiic control machine, an air traffic control machine has been partially shown with the illustrated embodiment of the present invention to lend emphasis to the utility of this invention. As mentioned above, the present invention is decidedly applicable where it is desired to either construct an air tratlic control system or further modify an already established system wherein changeable display indicators are employed. In this respect, various push buttons are shown with the included air traffic control machine which are employed for causing various operations of changeable display indicators including the posting of flight data. An air trafiic control system wherein changeable display indicators are employed and with which the present invention is applicable is shown and described in the pending application, Ser. No. 851,682, filed on November 9, 1959, by R. F. Albrighton and W. R. Smith. A system is disclosed in this application Ser. No. 851,682 which has provision for a variable number of altitudes, each such altitude being represented by a group or module of changeable display indicators. Also, this basic system once established provides that the changeable display indicators may be added to the system in modules as is desired. The present invention thus finds its utility at least in the construction of a machine where such air tralhc control system is employed, but it should be understood that the present invention is applicable to other types of display systems wherein changeable display indicators of different coded and non-coded types are employed.

Referring to FIG. 1A, a control panel Cl is shown therein which has different groups of push buttons located thereon having the functions fully described in the above identified pending application. A flight data key board is located on the control panel CP Where push buttons are provided for the digits 1 through 9 and O and the letters A through Z. Push buttons are also located on the control panel CP adjacent the flight data key board which are described in the above identified pending application as reservation buttons and a blanking button. These buttons are designated GRN, AMB, and BLK. Data correction buttons C2 through Clh are disposed above the flight data key board in position and are provided for permitting correction of the display for a particular changeable display indicator in any desired module of indicators. In addition, cancel and reset push buttons are provided for controlling the air trailic control. system to it at-rest position in the manner described in the above identified pending application. The control panel Cl is indicated to be held in position by the bolts 9 while a handle lid is provided for removing the control panel C? from an enclosure or structure housing control apparatus. The changeable display indicators are placed on top of the control panel C? in module form with one module being stacked or placed on top or" another module of changeable display indicators and are held in position by the bolts 11. Each of the altitude modules designate 1AM, 2AM, 3AM, 4AM and SAM is seen to include ten changeable display indicators such as changeable display indicators 15 through {or altitude module 1AM. Also, each all e module has included therewith an altitude selecting push button and a transfer push button such as altitude selecting push button A1 and transfer push button T1 for the altitude module 1AM. It will be noted that the first changeable indicator located adjacent the respective transfer push buttons in the different altitude modules is indicated to display an altitude reservation, whereas the remaining changeable display indicators in each altitude module display flight data. In this connection, the colors and symbols for the different altitudes reservations are shown in the chart of FIG. 1B. The changeable display indicator 15, for example, is shown to be displaying the symbol having a color red which is indicative of distant occupancy. The remaining changeable dislay indicators in altitude module 1AM are shown to be displaying digits and letters which are representative of flight data. The manner in which these push buttons are employed to cause operation of the changeable display indicators is described in the above identified pending application and need not be further considered herein.

The changeable display indicators mentioned above as being employed in the system disclosed in the above mentioned pending application, Ser. No. 851,682 are of the coded type dicloscd in the pending application, Ser. No. 763,569, filed on September 26, 1958 and entitled Data Posting Indicators, by W. D. Maynard. In this disclosure, two indicator tructures are shown, one for a 36-position indicator and the toher for a 12-po" on indicator. The main difierence between such indicators is in the number of control buses required to provide control energy in different code combinations for the operation of such indicators. The 36-position indicator requires eight control buses while the l2-position indicator rcquires six control buses. In the illustrated embodiment of this invention, the 36-position indicators are employed, but it should be understood that the l2-position indicator could as well be employed with modifications being made in connection with the number of control buses.

Referring to FIG. 2, an isometric view partially showing the air traliic control machine is shown with a portion of the covers 27, 28, 29 and 36 broken away to illustrate the manner in which the present invention is employed, and the manner in which connections are made to altitude selecting push button A3 and transfer push button T3. It will be noted that three altitude modules, 1AM, 2AM, and 3AM, of changeable display indicators are shown to be disposed in modular form over the enclosure or structure 26 within which the control panel CP is inserted. Connection is, under normal conditions, made to the control apparatus included within the structure 26 by wire connection to the printed circuit boards which are associated with the changeable display indicators. Because of the confusion which would necessarily result if all such Wire connections were made in the drawing shown in FIG. 2, no such wire connections are shown therein, but a detailed drawing of the wire connections to the individual printed circuit boards is shown in FIG. 8 and will be discussed later. It is shown in F1512, however, how the printed circuit boards which are associated with changeable display indicators having corresponding positions in their respective modules are electrically and physically connected to the printed circuit boards of all other changeable display indicators in that particular position. Also, it is shown how the printed circuit boards associated With the respective changeable display indicators for a module are rigidly held in their placed positions by a rectangularly shaped bar which is secured adjacent the common ends of all such printed circuit boards.

It will be noted that the changeable display indicators 24, 33 and 34 shown in FIG. 1A are located one above the other with the indicator 24 being at the bottom and indicator 34 being at the top with such indicators being included in the altitude modules 1AM, 2AM and SAM respectively. By referring to PEG. 2, it can be seen how the present invention is employed to mechanically and electrically connect these changeable display indicators. More particularly, a printed circuit board is provided for each of the indicators on which the respective control circuits are mounted, each of which is connected to the respective indicator. For example, the printed circuit boards 37, 38 and 39 correspond respectively to the indicators 24, 33 and 34. The changeable display indicators 24, 33 and 34 and their respective control circuits are connected to control energy and to each other through the connectors 4b and 41. Each such connector 40 and 41 is seen to connect corresponding connections for each of the printed circuit boards, eight of such connections being the control buses over which control energy is suppliable in dillerent combinations, while the remaining two connections are for supplying control energy to the control circuits. A rigidly formed bar of suitable material is employed to hold the printed circuit boards for each altitude module and connectors in a secured position. The bars 43, 44 and 45 are shown to be in secured positions for holding the respective printed circuit boards and connectors in their positions. For example, the bar 45 is held rigidly against one end of all connectors connecting the printed circuit boards associated with indicators in altitude modules 2AM and SAM by the nuts 4? and 4-9. This apparatus shown in FLG- 2 is enclosed by the covers as, 29 and 3% which for purposes of illustration are partially broken away as shown therein. Each of the covers 23 and 25 is shown to be three-sided having one common end thereof offset in order that the cover may be set on a similar cover or the base structure 26. Clips 52 (not all shown) are provided with each of the covers 28, 29 and Bill for further securing it in its placed position. Also, cover Bil has a fourth side normal to the three sides for enclosing the exposed top portion of the apparatus mentioned above. It will be noted that all connections are not shown on the printed circuit boards shown in PEG. 2 inasmuch as the showing thereof would unduly complicate such drawing shown in FIG. 2.

Referring to FIG. 3, a detailed drawing is shown of the elements employed in the combination of the present invention and, more particularly, the intended connections to be made between such elements for connecting changeable display indicators 33 and 34. The printed circuit boards 38 and 39 each have a printed circuit connector 5d which is adapted to engage a portion of the respective printed circuit boards 53 and 59 included with indicators 33 and 34. For example, the printed circuit connector attached to the printed circuit board 38 is partially broken away to show the spring biased connectors 53 and 54 included therewith each of which is adapted to engage a conductor mounted on either side of the printed circuit board 53 included with changeable display indicator 33. The connectors 53 and 54 are further connected to circuits included with the printed circuit board 38. The printed circuit boards 38 and 39 are shown in an assemling position for further mechanically and electrically being connected together by the connector 51. It will be noted that similar circuits for each of the boards 38 and 3& are indicated to be normally connected together by the connector 41 in assembled positions with the similar circuits including the common control buses over which con trol energy is suppliable to both changeable display indicators 33 and 3 in this instance. The connector ll is shown to have a bore as cut therein into which a shaft 62 included with the bar $5 is inserted when such bar 4-5 is placed in its secured position. It will also be noted that each of the printed circuit boards 38 and 39 include bevelled edges 64 and 65 for facilitating in the connection of respective connectors. Each connector such as connector 41 must slide over at least a portion of adjoining printed circuit boards such as boards 38 and 35 when it becomes necessary to replace one of the printed circuit boards in an assembled air traffic control machine as shown in FIG. 2.

The connector 4-1 is shown in a more detailed manner in FIGS. 4, 5 and 6. Referring to FIGS. 4, 5 and 6, it is seen that the connector 41 is formed in an elongated manner of a suitable insulating material and has a plurality of spring biased connectors 66 formed of a suitable metal which are adapted to engage the connections on the printed circuit boards. The connector 41 has a plurality of slots 67 cut therein transversely to the length of connector 41, each for receiving one of the spring biased connectors 66. With particular reference to FIG. 5, each of the spring biased connectors 66 is seen to be held in position by an insulating rod 68 with the free ends of the spring biased connectors being inserted into slots 67 cut into the connector 41. Also, each of the free ends of the spring biased connectors 66 has a raised portion with respect to the opposite surface of connectors 41 located in the slots 76 and 71 which is adapted to engage a connection disposed on the printed circuit boards. It will also be noted that each spring biased connector 66 is formed in a manner to leave an opening between the connector ill and two portions thereof for providing a resiliency of the spring biased connector 66.

On the reverse side of the printed circuit boards, all of the elements which may be included in the control circuits for respective changeable display indicators are located. More particularly, referring to FIG. 7, the reverse side of printed circuit board 33' is shown with several typical elements being located thereon in their respective positions which are included with the control circuit for changeable display indicator 33. These typical elements include transistors 74 and 75, diodes 7d and 77, and a resistor 73. It should be understood that a plurality of resistors and diodes are additionally normally included in the control circuit for the type of changeable display indicator employed in this invention but for simpllicity in the illustration of the printed circuit board 33, only these few typical elements are shown for illustrative purposes. It has been mentioned above that each of the changeable display indicators is effectively isolated from all of the other changeable display indicators having the corresponding position in their respective modules. In this connection, diode 77 is one of eight such diodes which normally would be included for isolation purposes in the connection of control energy over the control buses to the changeable display indicator 33. Other connections of the printed circuit board 33 to control energy for the operation of indicator 38' are made through the individual connectors 86, 81 and 82. Each of such connectors '80, 81 and 82 are connected to a wire which is further indicated to be connected to control energy.

With reference to FIGS. 3 and 7, it may be seen how each of the printed circuit connectors 55 have their spring biased connectors electrically connected to the respective printed circuit board. More particularly, referring to the printed circuit board 38 shown in FIGS. 3 and 7, it is seen that the spring biased connectors 53 and 54 have extensions which are soldered to the connections 56 and 57 which connects the indicator 33 to a circuit on the printed circuit board 3 8. It will be noted that the extensions of spring biased connectors 53 and 54 are of different lengths due to the manner in which the printed Z circuit board connector 55 is mounted on the board 38. The extensions of spring biased connectors 53 and d are only partially included in PEG. 7 for showing the connections to which they are suitably soldered as located on the printed circuit board 33.

It has been mentioned above that the wire connections to the printed circuit boards have been omi ed due to the complexity of the isometric view shown in PEG. 2. Referring to PEG. 8, the wire connections are shown to be made to all printed circuit boards associated with the changeable display indicators, the altitude selector push buttons and the transfer push buttons included in the altitude modules 1AM, 2AM and 3AM. All Such wire connections are made with the use of connectors similar to connectors 80, 82, and 32 shown in FEGS. 7 and 8. Each of the indi idual connectors shown in PlG. 8 including connectors St), 81 and 32 has substantially rounded sides which effectively provides a spring biased arrangement for facilitating the insertion to its connected position and yet providing a good electrical connection. All of the wire connections taken from the printed circuit boards are distributed to appropriate electrical apparatus included within the control panel structure as indicated by the arrow to the block 85. In this regard, the wire connections are not in any manner attached to the respective bars 43, 54 and i5, but they may at some point rest against such bars 43, 44 and 45 without resulting in electrical interference. It will also be noted that the printed circuit boards and the connectors employed to mechanically and electrically connect such printed circuit boards are held in position by the bars 43, 44 and 45.

It is believed that the nature of the invention, its advantages and characteristic features can be best understood with further description being set forth from the standpoint of procedure when adding a module of changeable display indicators to an already established air trafiic control machine and when replacing a printed circuit board for a particular changeable display indicator.

Let it be assumed that it is desired to include the changeable display indicators of altitude module 3AM with the air traihc control machine as shown in FIG. 2 and the required control circuits included with respective printed circuit boards also being added. Initially, the altitude module 3AM would be placed above the altitude module 2AM and secured in such position by the bolts 11. All of the changeable display indicators for the altitude module 3AM would then be added in addition to the push buttons A3 and T3. A printed circuit board having the control circuit for an indicator included therewith would next be inserted with each of the changeable display indicators and printed circuit boards for the buttons A3 and T3 would additionally be included and placed in position. A connector such as connector 41 would then be placed in position between printed circuit boards located one above the other and would be slid into position as mentioned above thus connecting control buses for each column of indicators. In order to hold such apparatus in position, the bar would then be placed in position so that each of the shafts thereon would be inserted in a bore cut into the respective con nectors and bolted into position by the bolts 4-3 and 49. The necessary wire connections would be made to the respective printed circuit boards by individual connectors as shown in FIG. 8 for supplying controlling energy to the control circuits associated with each of the printed circuit boards.

Let it be assumed that it is desired to replace the printed circuit board 38 with a similar printed circuit board. It is initially required to remove the bar 45 from its secured position as determined by bolts 72 and 73. The individual connectors so, Sit and 82. are then removed from the printed circuit board 38. In this connection, it should be understood that only the connectors 8t), 81 and 82 need be removed and all other connectors for the respective printed circuit boards associated with the indicators of module 2AM are left in position when the bar 44 is removed from its secured position. The Wires leading to such individual connectors are not in any Way fastened to the bar 45 and may be moved in order to remove such bar 45. After the connectors 30, 81 and 32 are removed from the printed circuit board 38, connectors 40 and 41 are slid out of their placed positions which then provi access to the printed circuit board 33. The printed circuit board may then be removed and replaced by a similar printed circuit board. "Elie reverse procedure is then required in order to replace the connectors 4t) and '41, the caring biased connectors 8t), 81 and S2, and the bar 4 The foregoing description has been given with respect to typical procedures which may be employed in practicing the present invention, but it should be understood that such typical procedures may be modified to a certain extent as is desired. Irrespective of the procedure employed, however, it is apparent that the recited objects of this invention are cliectively fulfille Summary From the consideration of the present invention, it is apparent that a novel combination of elements is shown and described which may be employed to modify an air trahic control machine in accordance with the requirements of increased air trafiic. Such an air traffic control machine may be thus installed in a particular location and thereafter be flexible in adapting to the demands of air tratfic as governed by that location.

Moreover, the individual elements of the novel combination of elements are constructed in a manner to facilitate the assemblage and maintenance of an air trathc control machine. That is, the individual elements for controlling the respective changeable display indicators may be separately removed and replaced without requiring any soldering. Also, a novel connector is shown and described which is employed to connect the printed circuit boards associated with changeable display indicators having corresponding positions in their modules without requiring any soldering.

Having described an air traffic control machine, as one specific embodiment of the present invention, it is desired to be understood that this form is selected to facilitate in the disclosure of the invention rather than to limit the number of forms which it may assume; and, it is to be further understood that various modifications, adaptations and alterations may be applied to the specific form shown to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention.

What we claim is:

1. An air trailic control machine for posting flight data for several flight altitudes comprising:

(a) a row of several posting indicators for each of the several flight altitudes,

(11) said rows being stacked one above the other,

(c) a circuit board, for the control of each posting indicator, extending longitudinally from one end of its associated posting indicator having several conductors extending transversely between a lower and an upper edge, and

(d) a quickly detachable connector disposed longitudinally between the lower edge of each of the circuit boards and the upper edge of a circuit board for the next lower flight altitude for connecting said conductors of the boards in respective columns.

2. An air trafilc control machine according to claim 1 wherein the circuit boards are printed circuits having a plurality of printed conductors extending transversely between their upper and lower edges.

3. An air traffic control machine according to claim 1 wherein a quickly detachable connector is provided for detachably connecting each of the circuit boards to its associated posting indicator.

4. An air trafiic control machine for posting flight data for several flight altitudes comprising:

(a) several laterally disposed posting indicators arranged in rows and columns for posting flight information, one row of indicators being provided for each of the flight altitudes,

(b) printed circuit control boards for the respective posting indicators disposed elevationally in columns and extending longitudinally from one end of their associated posting indicators,

(c) quickly detachable connectors disposed longitudinally between the circuit boards in each column,

(d) each of the connectors having oppositely disposed longitudinal slots formed therein for receiving edges of the circuit boards for adjoining flight altitudes, and

(e) the longitudinal slots of each connector containing the ends respectively of several elevationally disposed conductors for closing several circuit connections be- 1Q tween the circuit boards having their edges inserted in said slots.

5. An air trafiic control machine according to claim 4 wherein the connectors of each row are supported by a single support yoke that is quickly detachable from the connectors of that row.

6. An air trafiic control machine according to claim 4 wherein the conductors are of resilient material and are inserted in respective transverse slots formed in each connector and wherein a longitudinal pin of insulating material is provided for locking the conductors Within the transverse slots of each block.

References Cited in the file of this patent UNITED STATES PATENTS 2,410,540 Wight et a1 Nov. 5, 1946 2,535,954 Preston et a1 d. Dec. 26, 1950 2,661,465 Molnar Dec. 1, 1953 2,811,700 Kuch Oct. 29, 1957 2,857,577 Vanderpool Oct. 21, 1958 

4. AN AIR TRAFFIC CONTROL MACHINE FOR POSTING FLIGHT DATA FOR SEVERAL FLIGHT ALTITUDES COMPRISING: (A) SEVERAL LATERALLY DISPOSED POSTING INDICATORS ARRANGED IN ROWS AND COLUMNS FOR POSTING FLIGHT INFORMATION, ONE ROW OF INDICATORS BEING PROVIDED FOR EACH OF THE FLIGHT ALTITUDES, (B) PRINTED CIRCUIT CONTROL BOARDS FOR THE RESPECTIVE POSTING INDICATORS DISPOSED ELEVATIONALLY IN COLUMNS AND EXTENDING LONGITUDINALLY FROM ONE END OF THEIR ASSOCIATED POSTING INDICATORS, (C) QUICKLY DETACHABLE CONNECTORS DISPOSED LONGITUDINALLY BETWEEN THE CIRCUIT BOARDS IN EACH COLUMN, (D) EACH OF THE CONNECTORS HAVING OPPOSITELY DISPOSED LONGITUDINAL SLOTS FORMED THEREIN FOR RECEIVING EDGES OF THE CIRCUIT BOARDS FOR ADJOINING FLIGHT ALTITUDES, AND (E) THE LONGITUDINAL SLOTS OF EACH CONNECTOR CONTAINING THE ENDS RESPECTIVELY OF SEVERAL ELEVATIONALLY DISPOSED CONDUCTORS FOR CLOSING SEVERAL CIRCUIT CONNECTIONS BETWEEN THE CIRCUIT BOARDS HAVING THEIR EDGES INSERTED IN SAID SLOTS. 